1. Field of the Invention
The present invention relates to a sphygmomanometer air connector for pneumatic connection between a sphygmomanometer body and a pneumatic cuff.
2. Brief Description of the Prior Art
The sphygmomanometer has a built-in air system including a compression pump, a pressure sensor for detecting the pressure of a pneumatic cuff, a slow-speed exhaust valve and so on. For sphygmomanometry, the air tube of the cuff is connected to the above pneumatic system through an air connector and the cuff is compressed by the compression pump (not shown). In the actual determination of arterial blood pressure, the pneumatic cuff is set on the upper arm of the subject and the air compressed by the compression pump is delivered to the pneumatic cuff to arrest the blood flow in the bracheal artery. Then, in the slow exhaust or deflation stage, the appearance and disappearance of the Korotkoff sounds are detected and the cuff pressure at the appearance of the K sounds is taken as the systolic blood pressure while the cuff pressure at the disappearance of the sounds is regarded as the diastolic pressure.
The sphygmomanometer is subject to the Metric Law which provides that air leaks shall not be more than 4 mmHg in 3 minutes and, as such, is assayed item-by-item by the metric assay authority. When a sphygmomanometer is subjected to this assay with the air system of the sphygmomanometer body connected to the assay air system at the authority, compressed air must be supplied exclusively to the built-into pressure gauge (pressure measuring means) of the sphygmomanometer. For this purpose, it is the usual practice to either plug the exhaust valve or clip the air line of the exhaust valve to block the air flow. However, these procedures are inconvenient in that prior to assay, the cover must be removed from the sphygmomanometer body.
Therefore, the present applicant previously proposed a sphygmomanometer air connector as illustrated in FIG. 5(A) and (B).
This sphygmomanometer air connector comprises, as used in association with a sphygmomanometer body 61, an air socket 65 having a pressure measuring air line 63 and an exhaust air line 64 each communicating with an air plug acceptor 62, a short-length air supply plug 67 [See FIG. 5(B)] which is dismountably connected to the air plug acceptor 62 of said air socket 65 and has an air supply line 66 adapted to communicate, upon installation of the plug 67, with the pressure measuring air line 63 and exhaust air line 64 of said air socket 65, a long-length pressure assay auxiliary plug 69 which is dismountably connected to said air plug acceptor 62 of air socket 65 and upon installation thereof, obstructs said exhaust air line 64 of air socket 65, with its air supply line 68 alone being brought into communication with said pressure measuring air line 63.
In measuring the blood pressure, the short-length air plug 67 illustrated in FIG. 5(B) is inserted into the air socket 65. The air plug 67 is provided with a joint 67a for connection of the air tube of the pneumatic cuff at one end (base) thereof, while the tapered portion 67b at the other end (tip) is abutted against a tapered wall 65a at the plug acceptor 62 of the air socket 65. Upon insertion, the forward end of the air plug 67 is detained short of the position of the exhaust air line 64 and that of the pressure measuring air line 63, with the result that the pressure measuring air line 63 and exhaust air line 64 are brought into communication with the air supply line 66 of the air plug 67. Stated differently, the air system of the sphygmomanometer communicates with the pneumatic cuff. Hence, sphygmomanometry can be executed.
In the pressure assay, the long-length auxiliary plug 69 is inserted into the air socket 65 [See FIG. 5(A)]. That is to say, the air plug 67 fitted into the air socket 65 is disconnected and instead, the auxiliary plug 69 is inserted. The auxiliary plug 69 is formed at one end (base) thereof with a joint 69a' for connection of the air tube of the assay pneumatic system and at the other end a tapered portion 69b complementary with the taper 65a of the air socket 65, with a forward reduced-diameter part 69c of said tapered portion 69b being provided with an opening 69d which communicates with the air supply line 68 and a closure rubber piece 69e being attached to the forward end of said reduced-diameter part 69c. Therefore, upon insertion of the auxiliary plug 69, the closure rubber piece 69e obstructs the exhaust air line 64 of air socket 65, while the opening 69d is brought into communication with the pressure measuring air line 63. Stated differently, only the exhaust air line 64 of the air socket 65 is obstructed. Therefore, the pressure assay of the sphygmomanometer can be properly executed.
In the above sphygmomanometer air connector which was previously proposed by the present applicant, sphygmomanometry and pressure assay can be selectively performed by the mere procedure of inserting either the air plug or the auxiliary plug into the air socket exposed on the surface of a sphygmomanometer body. Therefore, the troublesome procedure of removing the cover from the sphygmomanometer body for each blood pressure determination or pressure assay and reinstalling the cover after the determination or assay was overcome.
However, this sphygmomanometer air connector requires an auxiliary plug for pressure assay in addition to the air plug for blood pressure determination. Therefore, the product sphygmomanometer must be supplied with the auxiliary plug, which is unnecessary for blood pressure determination, as an attachment, thus contributing to an increased product price but an increased risk of missing the auxiliary plug which is not frequently used.